Autonomous vehicles may employ a plurality of sensors providing a controller or controllers with situational-awareness data including image data indicative of traffic, proximity to other vehicles, traffic control signals, traffic lane locations, etc. Such sensors may include visual sensors, e.g., cameras and LIDAR sensors. One location for visual sensors is a roof of the vehicle. The sensors may be placed in a protective pod on the roof of the vehicle. However, such pods may become very warm on sunny days, and sensor windows in the pods may become fogged or frosted with high humidity and cold temperatures. It is a problem to prevent the temperature in the pod from exceeding an acceptable operating temperature for the sensors, and to prevent windows in the pod and the sensors from becoming fogged or frosted.